Methods and systems for image data processing

Abstract

Methods, storage mediums, and systems for image data processing are provided. Embodiments for the methods, storage mediums, and systems include configurations to perform one or more of the following steps: background signal measurement, particle identification using classification dye emission and cluster rejection, inter-image alignment, inter-image particle correlation, fluorescence integration of reporter emission, and image plane normalization.

What is claimed is: 
     
       1. A non-transitory, computer-readable medium storing instructions that when executed by a computer system cause the computer system to perform operations comprising:
 selecting, using an analysis of an image of particles having fluorescent material associated therewith, a first set of pixels in the image, wherein members of the first set of pixels have a value for an optical parameter that is above a specified threshold; 
 identifying a first location within the first set of pixels that has a first maximum value of the optical parameter within the first set of pixels, wherein identifying the first location includes:
 analyzing the pixels in the first set of pixels to identify a first peak pixel that exhibits the first maximum value for the optical parameter within the first set of pixels, and 
 identifying an off-center portion of the first peak pixel as the first location based on integrating the optical parameter values of pixels within a specified radius of the first peak pixel; 
 
 subsequently computing a first rate of change of the value of the optical parameter for pixels that are within a specified distance of the first location; and 
 determining, based on the first rate of change of the value of the optical parameter, whether to perform further image processing on the first set of pixels. 
 
     
     
       2. The computer-readable medium of  claim 1 ,
 wherein the image includes the first set of pixels and a background signal, 
 wherein members of the first set of pixels has a value for an optical parameter at least twice as intense as a value for the optical parameter of the background signal; and 
 wherein the selecting includes comparing the value for the optical parameter of the first set of pixels to the value for the optical parameter of the background signal. 
 
     
     
       3. The computer-readable medium of  claim 1  wherein the operations further comprise:
 selecting, using the analysis of the image, a second set of pixels of the image, wherein members of the second set of pixels have a value for an optical parameter that is above a specified threshold; 
 identifying a second location within the second set of pixels that has a second maximum value of the optical parameter within the second set of pixels; 
 computing a distance between the first location and the second location; and 
 determining whether to accept the first set of pixels for further evaluation based on the distance between the first location and the second location. 
 
     
     
       4. The computer-readable medium of  claim 3 , wherein determining whether to accept the first set of pixels is based on the distance between the first location and the second location being greater than a projected diameter of one of the particles. 
     
     
       5. The computer-readable medium of  claim 1  wherein identifying an off-center portion of the first peak pixel as the first location is based on determining that a dimension of the location of the off-center portion is greater than a threshold percentage of a single pixel width within the image. 
     
     
       6. The computer-readable medium of  claim 1 , wherein the operations further comprise:
 selecting, from the analysis of the image, a second set of pixels, wherein members of the second set of pixels have a value for an optical parameter that is above a specified threshold; 
 identifying a second location within the second set of pixels that has a second maximum value of the optical parameter within the second set of pixels; 
 subsequently computing a second rate of change of the value of the optical parameter for pixels that are within a specified distance of the second location; and 
 determining whether to accept the first set of pixels for further evaluation based on a comparison between the first rate of change and the second rate of change. 
 
     
     
       7. The computer-readable medium of  claim 1 ,
 wherein computing the first rate of change of the value of the optical parameter includes:
 calculating a first sum of optical parameter values for pixels within a first radius surrounding the first location; 
 calculating a second sum of optical parameter values for pixels within a second radius surrounding the first location, wherein the second radius is greater than the first radius; and 
 
 wherein determining whether to perform further image processing on the first set of pixels is based on a ratio of the first sum to the second sum being greater than a threshold ratio. 
 
     
     
       8. A method comprising:
 selecting, using an analysis of an image of particles having fluorescent material associated therewith, a first set of pixels of the image, wherein members of the first set of pixels have a value for an optical parameter that is above a specified threshold; 
 identifying a first location within the first set of pixels that has a first maximum value of the optical parameter within the first set of pixels; 
 subsequently computing a first rate of change of the value of the optical parameter for pixels that are within a projected diameter of a particle represented by the first location; and 
 determining, based on the first rate of change of the value of the optical parameter, whether to perform further image processing on the first set of pixels. 
 
     
     
       9. The method of  claim 8 , wherein the optical parameter comprises an intensity of fluorescence. 
     
     
       10. The method of  claim 8 ,
 wherein the image includes the first set of pixels and a background signal, 
 wherein members of the first set of pixels have a value for an optical parameter at least twice as intense as a value for the optical parameter of the background signal; and 
 wherein the selecting includes comparing the value for the optical parameter of the first set of pixels to the value for the optical parameter of the background signal. 
 
     
     
       11. The method of  claim 8  further comprising:
 selecting, using the analysis of the image, a second set of pixels of the image, wherein members of the second set of pixels have a value for an optical parameter that is above a specified threshold; 
 identifying a second location within the second set of pixels that has a second maximum value of the optical parameter within the second set of pixels; 
 computing a distance between the first location and the second location; and 
 determining whether to accept the first set of pixels for further evaluation based on the distance between the first location and the second location. 
 
     
     
       12. The method of  claim 8  further comprising:
 analyzing pixels in the first set of pixels to identify a first peak pixel that exhibits the first maximum value for the optical parameter within the first set of pixels; and 
 identifying a central portion of the first peak pixel as the first location. 
 
     
     
       13. The method of  claim 8 , wherein determining the first location includes:
 analyzing pixels in the first set of pixels to identify a first peak pixel that exhibits the first maximum value for the optical parameter within the first set of pixels; and 
 identifying an off-center portion of the peak pixel as the first location based on integrating the optical parameter values of pixels within a specified radius of the first peak pixel. 
 
     
     
       14. The method of  claim 8  further comprising:
 selecting, from analysis of the image, a second set of pixels, wherein members of the second set of pixels have a value for an optical parameter that is above a specified threshold; 
 identifying a second location within the second set of pixels that has a second maximum value of the optical parameter within the second set of pixels; 
 subsequently computing a second rate of change of the value of the optical parameter for pixels that are within a specified distance of the second location; and 
 determining whether to accept the first set of pixels for further evaluation based on a comparison between the first rate of change and the second rate of change. 
 
     
     
       15. The method of  claim 8 ,
 wherein computing the first rate of change of the value of the optical parameter includes:
 calculating a first sum of optical parameter values for pixels within a first radius surrounding the first location; 
 calculating a second sum of optical parameter values for pixels within a second radius surrounding the first location, wherein the second radius is greater than the first radius; and 
 
 wherein determining whether to perform further image processing on the first set of pixels is based on a ratio of the first sum to the second sum being greater than a threshold ratio. 
 
     
     
       16. A system comprising:
 an imaging subsystem configured to capture an image of particles having fluorescent material associated therewith; 
 a computer processor system; and 
 a computer memory storing instructions that when executed by the computer processor system causes the system to perform operations comprising:
 selecting, using an analysis of the image, a first set of pixels and a second set of pixels in the image, wherein members of the first set of pixels and the second set of pixels have a value for an optical parameter that is above a specified threshold; 
 identifying a first location within the first set of pixels that has a first maximum value of the optical parameter within the first set of pixels; 
 subsequently computing a first rate of change of the value of the optical parameter for pixels that are within a specified distance of the first location; 
 determining, based on the first rate of change of the value of the optical parameter, whether to perform further image processing on the first set of pixels; 
 identifying a second location within the second set of pixels that has a second maximum value of the optical parameter within the second set of pixels; 
 subsequently computing a second rate of change of the value of the optical parameter for pixels that are within a specified distance of the second location; and 
 determining whether to accept the first set of pixels for further evaluation based on a comparison between the first rate of change and the second rate of change. 
 
 
     
     
       17. The system of  claim 16 ,
 wherein the image includes the first set of pixels and a background signal, 
 wherein members of the first set of pixels within the image has a value for an optical parameter at least twice as intense as a value for the optical parameter of the background signal; and 
 wherein the selecting includes comparing the value for the optical parameter of the first set of pixels to the value for the optical parameter of the background signal. 
 
     
     
       18. The system of  claim 16 , wherein the specified distance comprises a projected diameter of the particle represented by the first location. 
     
     
       19. The method of  claim 8 , wherein identifying the first location includes:
 analyzing pixels in the first set of pixels to identify a first peak pixel that exhibits the first maximum value for the optical parameter within the first set of pixels; and 
 identifying a central portion of the first peak pixel as the first location. 
 
     
     
       20. The method of  claim 8 , wherein identifying the first location includes:
 analyzing the pixels in the first set of pixels to identify a first peak pixel that exhibits the first maximum value for the optical parameter within the first set of pixels; and 
 identifying an off-center portion of the first peak pixel as the first location based on integrating the optical parameter values of pixels within a specified radius of the first peak pixel.